


By chance

by LoveMeNot



Category: Haikyuu!!
Genre: Alternate Universe - Mermaids, Haikyuu!! Fantasy Exchange, M/M, fantasyhaikyuuminiexchange, mermaid
Language: English
Status: Completed
Published: 2019-05-11
Updated: 2019-05-11
Packaged: 2020-02-27 15:23:56
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,101
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18741760
Author URL: https://archiveofourown.org/users/LoveMeNot/pseuds/LoveMeNot
Summary: Iwaizumi couldn't wait to start working at one of Japan's most famous aquariums as a veterinarian. He had his roots in the sea and he absolutely adored the creatures roaming in it. But his assigned supervisor, Oikawa Tooru, turns out to be more interesting than he could predict upon first meeting.This fic was written for the fantasyhaikyuuexchange.





	1. Chapter 1

**Author's Note:**

  * For [TentacleBubbles](https://archiveofourown.org/users/TentacleBubbles/gifts).



> Hello there!  
> Staying inside 1050-word limit proved to be more difficult than I thought it would, but I hope it didn't affect the final version too badly.  
> Enjoy!

Iwaizumi walked into the aquarium feeling like a little kid: the giddiness of the first time washing over him and putting a skip in his steps. He was no longer a kid and he wasn’t a visitor either. Fresh out of college, he was starting his career as a marine veterinary at Okinawa Churaumi Aquarium.

His love for all marine creatures traced way back to when he was a 5-yo boy living right by the shore in a small and traditional village. The earfuls he got from his mother when he started bringing the live fishes and crabs he was able to capture with his net home still rang loud and clear in his head. As he grew up, his dream to save these beautiful creatures got clearer and closer as he found his way through his studies, always coming out on top. Which gave him recognition enough that he was immediately offered training at one of the best aquariums in Japan.

As he got to the office to ask for directions, he was intercepted by one of the staff members. The tall lanky man seemed to be around his age, if not younger. As their eyes met, though, Iwaizumi had a double take. Even though he had to admit that the man was attractive per se, his eyes were what really drew him in, making him feel as if he was drowning at sea. In his stupor he missed what was being said to him and, blushing in embarrassment, he asked the stranger to repeat himself.

“Ah, don’t worry. I always have this effect on people.” He sing-sang with a wink and a teasing smile (which did _not_ make Iwaizumi blush to the tip of his ears). “You must be the newbie, right? Well, I’m Oikawa Tooru, pleasure to meet you. I will be your guide from now on.”

“Um, yeah. Nice to met you too. Iwaizumi Hajime.” He stuttered and held out his hand to shake Oikawa’s who gladly grabbed it.

“Can’t wait to work side by side with you, Iwa-chan.” He chirped. “Are you ready to meet the belugas?”

“Yeah, sure.” He nodded, his blush intensifying at the cute nickname. “Shouldn’t I change first, though?”

“Right, right.” The other smiled. “I’m so used to be in here that I forgot you just arrived. Follow me, I’ll show you the lockers.”

Once Iwaizumi was out of his civilian clothes and clad with a thermo-resistant bodysuit, Oikawa showed him the way around the aquarium before bringing him to what he defined as “the best place in the world”. And as they walked into the secluded area, Iwaizumi not only understood why the other deemed it that way, but also had to fight his fist instinct, which was to squeal.

In the enclosures, rigorously kept at a constant low temperature to mimic the natural habitat of the majestic creatures, swam a mother-beluga with her newborn, their candid color contrasting with the deep blue of the whole room.

Iwaizumi thanked the darkness of the space around him for hiding the blush that once again burned under his skin as he met Oikawa’s smiling eyes across the space that separated them. As the other moved closer to the enclosure, gently laying a hand on the glass dividing them from the animals, Iwaizumi was hypnotized by the dancing lights playing on Oikawa’s skin. He kept watching, finally taking slow steps toward the other, as the baby beluga reached for Oikawa, smashing his face on the glass in an attempt to greet him, and causing a melodic laugh to fill the room.

It was right then and there that Iwaizumi realized that maybe, just maybe, he was a little starstruck and already crushing on the beautiful stranger.

* * *

  

Iwaizumi soon realized though that his chances of being reciprocated by Oikawa were near to none. Not only because the other was definitely out of his league to begin with, but also because he refused to share any detail of his life out of the aquarium, making any conversation not pertaining to work extremely one sided.

At least his work there was going swimmingly. Looking after the newborns and helping Oikawa with the training of young dolphins, orcas and seals, had easily become his favorite part of the day. What he didn’t like was returning home to his small studio alone, leaving Oikawa right in front of the entrance doors to the aquarium to find him there, waiting for him, the next morning with a new story about something cute some of the fishes had done while he was feeding them breakfast.

It was by chance that Iwaizumi’s worries (given by Oikawa’s strange habits and answers to his and other co-workers’ questions) were quenched, even if not in the way he had foreseen, aka Oikawa hating all the staff members.

After he had gotten home from work, he realized he had forgotten half of his belongings in his locker. It wouldn’t have been much of a problem if the aquarium wasn’t supposed to stay closed for the next week, which meant he had to go back and hope the back door for the staff would be open as per usual.

As he trekked back to the lockers, he was surprised to find that only the lights of the biggest fish tank were turned on. Nobody would have noticed unless they were to wander deep inside the building, and it was probably best that he had come soon enough to avoid wasting energy. Or that was what he thought until he realized that whoever had turned the lights on had done so on purpose, hoping not to be discovered.

When Iwaizumi’s eyes fell on the ginormous tank, his breath hitched, his eyebrows rose up and his mouth fell open. Oikawa was in the tank. But he wasn’t anything like he would have expected. He had discarded his usual skin tight swimsuit but instead of legs his lower half had become a fishtail, turquoise scales covering it from right under the man’s navel to the silky looking caudal fin, which was of a mesmerizing aquamarine. Scales were speckled like freckles on the man’s hands, shoulders and neck where gills had opened under his ears. And as if he had felt Iwaizumi’s presence, Oikawa turned around, meeting the other’s eyes.


	2. Chapter 2

“Iwa-chan?” Oikawa blanched; eyes filling with fear. “What are you doing here?”

Iwaizumi was still with shock, and the more his answer got delayed the more the merman panicked. Only when Oikawa reached for the edge of the tank to get out did Iwaizumi wake up from his stupor.

“You… are a mermaid?” He breathed out, trying more to convince himself that he wasn’t in fact dreaming.

“Surprise?” The other bitterly laughed, as he hitched himself on the edge with a powerful thrust of his tail.

“Don’t get out… I’m coming in… wait… just enough for me to change, okay?” Iwaizumi stuttered as he locked gaze with the other man, hoping the other was able to see his soul through his eyes and know that nothing had changed in his heart.

Oikawa didn’t have time to answer as he watched Iwaizumi run out of the room without looking back. He slipped back into the tank, his previous happiness at finally being freed of his human-looking constraints all but forgotten. Thankfully not even two minutes later a ripple in the surface alerted him of the other man presence in the tank.

Iwaizumi had always been a lost cause when it came to reading others’ (and sometimes his own) feelings, but Oikawa was making it easy for him, avoiding even turning toward him, shoulder tense and arms encircling his stomach protectively.

“Oikawa?” He tried. Approaching him as he would any of his scared patients, slow but confident that he would be able to help, somehow. He swam toward the other, his mind getting clouded with doubts as the dots slowly started to connect. All the times Oikawa refused invites to a drink after long hours at work, never ate at the canteen with everyone else, never went outside the aquarium’s premises, talked with the fishes as if they were able to listen, comprehend and answer, all the crazy stories he told and his quirks suddenly made sense.

“So, you do enjoy our company… you weren’t avoiding our co-workers’ and your fans’ invites to dinner willingly…” He realized. “You are held here like a prisoner… or am I making the last part up?”

“No, you aren’t…” Oikawa sullenly answered in a whisper.

“Oikawa, please turn around” he begged, not knowing how the other would react if he were to touch him.

“Are you scared of me yet, Iwa-chan?” The other breathed out as he turned, keeping his eyes tightly closed.

“I am scared _for_ you, Tooru…” He truthfully answered. “Are you safe here?”

“As safe as I will ever be…” He fake-smiled, finally meeting Iwaizumi’s eyes. Iwaizumi’s breath was stolen from his lungs as his eyes met the cobalt of Oikawa’s irises, so different from the caramel tinting them when he was disguised as a common human being.

“God, you are so beautiful…” Hajime confessed, closing the distance between them. That at least made the merman giggle.

“Such a romantic Iwa-chan.” He teased.

 “Anyway,” he started once again, “I’m not letting them hold you captive against your will. If you want to get out of here, I will help you as much as I can.”

“You don’t need to do that.” Oikawa sighed. “I traded my captivity for the secret to be kept. And I’m okay with being here… It just gets lonely sometimes. I miss the waves crashing on the shore.”

“Oh… Okay.” He pondered, his brain working out ways to get Oikawa out of the aquarium, even if just for a little vacation. He understood the reason behind the other’s actions, and he didn’t want to endanger yet another species, if he could help it.

“Iwa-chan, you should stop thinking, your brain won’t be able to sustain all that work at once!” Oikawa bantered, back to his usual self. The shock of being found out rapidly dissipating.

“Say that again, if you’ve got the courage, dumbass!” He joked, making what was left of the initial tense atmosphere disperse.

 

Minutes trickled into hours as Iwaizumi’s scientific curiosity took the best of him and he started questioning Oikawa about his life as a mermaid. The cold water started bothering him after a while and his eyes began fluttering closed more and more often in the early hours of the morning. But it wasn’t until Oikawa forcefully kicked him out of the tank that he realized just how long he had been soaking.

“Iwa-chan, if you aren’t careful, you’ll catch a cold! Go home!” the other screeched in a poor attempt to get him to move while also keeping him awake.

“Yeah yeah…” Iwaizumi yawned. “Can I come back tomorrow?”

“Sure… If I don’t bore you… That’d be amazing…” the other blushed. “Make sure to sleep though”

“I will…Goodnight Tooru…” He whispered as he finally convinced his limbs to climb down the stairs.

“Goodnight Hajime…” Oikawa breathed out as he watched the other disappear behind the door separating the room from the hallway leading to the lockers.

* * *

 

 

Just like that Oikawa’s usually boring and depressing off days became his favorite part of the week. And as he found himself enjoying the other’s company more and more with each passing hour, he understood the reason why his mother had fallen in love with a human, too.

The day he resolved to tell Iwaizumi his feelings was their planned vacation (which they had agreed upon with the director of the aquarium) to the other’s old village house. Doubts started creeping in only as they walked from the village to the secret cove Hajime had spoke about as he recounted his many adventures. But they rapidly dissipated as he realized that maybe the reasons behind Hajime uncharacteristic silence were the same behind his.

As their feet touched the soft sand Iwaizumi turned to him looking rather constipated, which made it almost impossible for Oikawa not to laugh in his face.

“I have something to tell you…” He tried, his gruff voice forcing his way out his tense chest.

“Me too, Iwa-chan.” He smiled, studying the other’s expression as his eyes became the size of saucers.

“Uh…” he scowled, unconvinced. “Then you go first”

“I love you, Iwa-chan” Oikawa breathed out feeling his heart squeeze inside his chest.

“I love you, too” He felt the other smile just a breath away from his lips before they met halfway.

**Notes for the Chapter:**

> I really hope you enjoyed it!


End file.
